Prior art includes U.S. Pat. No. 3,649,780 by Johnson and U.S. Pat. No. 4,450,323 by Iitsuka with rotary means of reversing the circuit; U.S. Pat. No. 3,800,103 by Hardi-Kern and U.S. Pat. No. 4,074,099 by Steen with reciprocating means of reversing the circuit.
Circuits in the above switches are reversed by hand levers or by fluid-pressure actuators. None of the switches is capable of automatically and continuously reversing the circuit for prolonged periods of time, which is the original, distinct and unique feature of the switch disclosed herein.